Optical disk with pre-recorded marker pattern
US4685096A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1985 |
| Grant date | Aug 4, 1987 |
| Priority date | — |
| Expiry date | Jul 10, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording disk comprises a track divided into sectors and having a longitudinal axis. Areas on this track for writing data using a predetermined increment alternate with prewritten marker areas. Each of these comprises at least two patterns having leading and trailing edges. Part of at least one of these patterns is offcenter relative to the track axis and associated with at least one edge of a pair of leading and trailing edges combined with another pair of leading and trailing edges to define along the axis two predetermined distances. Each of these distances is between two consecutive multiples of the data writing increment. The patterns are adapted to be scanned optically in succession by a read spot to detect any track following error, by virtue of interaction of the read spot with at least the offcenter pattern part, and with reference to a timebase synchronization signal resulting from interaction of the read spot with at least two leading edges and at least two trailing edges.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.